-- The 22-year-old Polish world number 43 is a low-key figure off court but when he's playing he has a "rip your heart out, this assassin type of energy" said his coach Craig Boynton, who counts former number one and Slam winner Jim Courier among his previous pupils.

Hurkacz thrives on hard courts. He reached the quarter-finals at Indian Wells were he beat Kei Nishikori and Denis Shapovalov before losing to Roger Federer.

A week later, he knocked world number four Dominic Thiem out of Miami.

On clay this spring, his best run was a third round slot in Madrid having come through qualifying.

-- Hanfmann is 27 years old and ranked at a lowly 184 in the world having turned professional relatively late in his career after a four-year US college stint in which he helped the University of Southern California win two national titles.

Having made it through qualifying in Paris, his match against 11-time champion Rafael Nadal will be his first on the main tour this year.

Has never won a main draw match at the Slams and his form reflects that statistic.

In 2019, he has earned just $3,600 while world number two Nadal has banked $3.7 million in the same period.

-- Sonego, a 24-year-old Italian, is ranked 73 and is a potential banana skin for Federer having made the quarter-finals at the Monte Carlo Masters this year after qualifying. He was also in the last-eight on clay at Marrakech.

Sonego fell in qualifying at Roland Garros in 2018 while best run at a Slam was a second round appearance at the 2018 US Open.

Anna Karolina Schmiedlova v Naomi Osaka (world number one and reigning US and Australian Open champion, two-time major winner)

Head-to-head: First meeting

Schmiedlova's Roland Garros best: 3rd rd 2015

-- A former top 30 player, the 24-year-old Schmiedlova is now at 92 in the world but boasts solid form at Roland Garros having defeated Venus Williams on her way to the third round in 2015.

The Slovak also has three titles -- two on clay -- and has been a runner-up on two occasions including at Hobart in January.

-- Diatchenko is a 28-year-old Russian, ranked at 82 in the world, but with the capability to shock the big names, famously beating Maria Sharapova in the first round at Wimbledon in a three-hour epic last year.

Diatchenko has been plagued by injuries, particularly with ligament and Achilles setbacks.

She admits that she returned from surgery too rapidly at the US Open in 2015 where she was forced to retire from her first round match -- against Serena Williams.